Using the Q6 Modifier for Outpatient Physical Therapy

The Q6 modifier identifies an outpatient physical therapy service furnished by a substitute physical therapist under a fee-for-time compensation arrangement. Under Section 16006 of the 21st Century Cures Act, a physical therapist enrolled in Medicare may use a substitute PT to provide services in a designated Health Professional Shortage Area (HPSA), Medically Underserved Area (MUA), or rural area, and still bill Medicare — as long as the arrangement is documented and coded correctly.

This is most useful when a therapist in your group has to take an unexpected leave of absence and you need a substitute to keep seeing patients without interrupting billing.

Q6 vs. Q5: fee-for-time vs. reciprocal billing

Medicare recognizes two substitute-billing arrangements, and they’re coded differently:

• Q6 — Fee-for-time compensation. A per-diem arrangement billed under the NPI of the physical therapist being replaced. Append modifier Q6 to identify services furnished by the substitute.
• Q5 — Reciprocal billing. Each therapist normally bills their own patients; under a reciprocal arrangement the substitute reassigns benefits to the group. Append modifier Q5.

Either modifier goes on the CMS-1500 form (or its 837P electronic equivalent).

When substitute services are reimbursable

Services provided by a substitute physical therapist may be reimbursed when:

• The regular physical therapist is unavailable to provide the services;
• The Medicare patient has arranged or seeks to receive the services from the regular physical therapist;
• The substitute does not provide services to Medicare patients over a continuous period longer than 60 days.

The 60-day rule (and the military exception)

The continuous period begins on the first day the substitute provides covered visit services to Medicare Part B patients who would normally be seen by the regular therapist, and ends on the last day the substitute treats those patients. The period runs without interruption even on days no covered services are provided. A new period can begin once the regular therapist returns to work.

Exception: there’s an active-duty exception for a therapist called to serve in the military, which allows billing for an extended period beyond the 60-day limit.

Documentation you must keep

Keep a record of each service provided by the substitute physical therapist, along with the substitute’s NPI, on file. This record must be made available to Medicare on request. Always notate in the patient record when a substitute provided the service.

The short version

If a substitute PT covers for your regular therapist in an eligible area, use Q6 for fee-for-time (per-diem, billed under the regular therapist’s NPI) or Q5 for reciprocal billing, stay inside the 60-day window, and document every visit with the substitute’s NPI. Coded and documented correctly, you keep billing Medicare without interruption.

Reference: CMS Internet-Only Manual (IOM), Pub. 100-04, Medicare Claims Processing Manual, Ch. 1, §§30.2, 30.2.1, 30.2.10, 30.2.11, 30.2.13, 30.2.14; CMS CR10090. Verify current guidance with your MAC before billing — payer rules change.

---

Spending more time on billing rules than on patients? We run billing and revenue cycle for therapy practices — clean claims, fewer denials, current rules. See our billing & RCM service or get a free consultation.